The create method I assume is from a user request, so it is a different HTTP request from the list. The data from the create method is long gone, and could even be in a different mongrel server.
If you want to highlight the last created record you will need to store in each record the creation time and the creating user, then compare those to the current user and highlight the newest record in the list. There are standard column names for time stamps that will be set by AR when a record is saved, but setting the user will need to be done in a before_save filter or in your app logic.
Michael